Valence band tail states in disordered superlattices embedded in wide parabolic AlGaAs well
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
06/11/2013
06/11/2013
2012
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Resumo |
Optical properties of intentionally disordered multiple quantum well (QW) system embedded in a wide AlGaAs parabolic well were investigated by photoluminescence (PL) measurements as functions of the laser excitation power and the temperature. The characterization of the carriers localized in the individual wells was allowed due to the artificial disorder that caused spectral separation of the photoluminescence lines emitted by different wells. We observed that the photoluminescence peak intensity from each quantum well shifted to high energy as the excitation power was increased. This blue-shift is associated with the filling of localized states in the valence band tail. We also found that the dependence of the peak intensity on the temperature is very sensitive to the excitation power. The temperature dependence of the photoluminescence peak energy from each QW was well fitted using a model that takes into account the thermal redistribution of the localized carriers. Our results demonstrate that the band tails in the studied structures are caused by alloy potential fluctuations and the band tail states dominate the emission from the peripheral wells. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4730769] FAPESP FAPESP CNPq CNPq |
Identificador |
JOURNAL OF APPLIED PHYSICS, MELVILLE, v. 111, n. 12, supl., Part 3, pp. 956-972, 42156, 2012 0021-8979 http://www.producao.usp.br/handle/BDPI/41980 10.1063/1.4730769 |
Idioma(s) |
eng |
Publicador |
AMER INST PHYSICS MELVILLE |
Relação |
JOURNAL OF APPLIED PHYSICS |
Direitos |
restrictedAccess Copyright AMER INST PHYSICS |
Palavras-Chave | #MULTIPLE-QUANTUM-WELL #MULTILAYER ELECTRON-SYSTEMS #STRONG MAGNETIC-FIELDS #TEMPERATURE-DEPENDENCE #CARRIER LOCALIZATION #EXCITON LOCALIZATION #HALL SUPERLATTICES #SEMICONDUCTORS #PHOTOLUMINESCENCE #EMISSION #PHYSICS, APPLIED |
Tipo |
article original article publishedVersion |